This invention relates to methods for making soil conditoners, and more particularly to a method for coloring and converting of softwoods shavings into a mulch for landscaping applications.
In the field of producing mulch for landscaping applications, it is highly desirable to produce a mulch with natural, dark color, and good moisture retention properties. It is known that many commonly produced mulches are artificially dyed to imitate natural colors. The dyes used for artificial coloration are known to shed water and/or inhibit water absorption. Furthermore, many of the dyes and emulsions used to artificially color mulch are known to contain ingredients which may be harmful when handled, or when leached into the soil and environment.
The attempt to produce mulch by artificially dying ingredients also incurs the use of specialty equipment, such as screeners, dryers, and the like. The costs of such equipment ranges upwardly from $60,000 to $200,000 and above. Mulch produced with such dyes, emulsions, and equipment adds as much as $4.20 per cubic yard of finished material.
Additionally, many commercially produced mulches contain undesirable ingredients, such as demolition debris, glass, plastic, creosoted wood, wood containing toxic preservatives, and some soil conditioners even contain sewage waste products.
Additionally, because of the manner in which ingredients are handled and processed, many mulches contain weed seeds which are undesirable in a landscaping product.
A superior mulch and soil conditioner will be produced by a process which uses only natural, organic ingredients, has a natural, permanent dark color, has an attractive texture, has good moisture retention properties, is free of toxic materials, is free of weed seeds, is safe for humans, pets, and other living things, and qualifies in any organic certification program.
The present invention embodies all of the aforementioned virtues in production and in the final product. A commonly used method for producing mulch which most closely resembles this invention, Zeager U.S. Pat. No. 4,788,790, is referred to in order to illustrate the drawbacks of that process and the improvements of this invention. In that patent, Zeager recommends, as an ingredient, 20% bark, preferably oak bark. Also, Zeager states a preferred temperature of 65 degrees to 85 degrees F (18.3 degrees to 29.3 degrees C) in order to produce the dark color for the mulch. Furthermore, Zeager finds faster processing in the summertime, and forms piles in long and low rows with a total volume ranging between 2800 and 9400 cubic yards. As may be seen from the foregoing, the bark used by Zeager is, of course, different than the combination of manure-softwood shavings recommended in the present invention. Also, the low temperature range used by Zeager is much too low to include biological activity as part of the manufacturing process. The recommendation by Zeager to perform his method in summer, avoids a more efficient processing during lower ambient temperatures with the present invention process. Furthermore, the conical shapes recommended in the present invention process accounts for the difference in the quantity of heat generated, 160 degrees to 200 degrees F (70 degrees to 93 degrees C) with the present invention, as compared to 65 degrees to 85 degrees F (18.3 degrees to 29.3 degrees C) noted by Zeager. Still further, the use of a crater and concentric troughs in the piles recommended in the present invention process, serves to increase the uniformity of saturation of liquid within the piles and proper compaction of the piles, when compared to the Zeager process. Lastly, the present invention produces a final pH value which is xe2x80x9csweetxe2x80x9d, and this is beneficial when used.with many types of landscaping plantings, whereas the same result is not achieved by Zeager.
Accordingly, a primary object of the present invention is to provide a process for producing mulch which is safe, non-toxic, weed-free, is able to qualify in organic certification programs, and results in mulch which is natural and darker colored for land-scaping applications.
A further object of the present invention is to provide a method for producing mulch which is lower in cost for equipment and ingredients than the methods presently available.
A further and more particular object is to provide a method for producing mulch resulting from the use of proper moisture and temperature levels, wherein biological activity is promoted in order to kill weed seeds and bake-in the desired color, which ranges from brown to black.
These and other objects of the invention are featured in a method for producing mulch which utilizes ripe de bois, softwood shavings that have been used as a bedding in horse stables and/or cow barns. Spent bedding ingredients are mixed with approximately 10% to 20% agricultural manure, by volume, so that a carbon-to-nitrogen ratio ranging from 100 to 200 parts carbon to 1 part nitrogen is. achieved. Other ancillary ingredients can be used in the mixture, but not to exceed 25% of the volume. Accordingly, the softwood shavings, by volume, constitute at least 60% of the mixture. Piles are formed of the mixed ingredients to achieve maximum compression, saturation, and optimal heat generation. The shapes of the piles are made in the form of cones, with concentric troughs and a crater truncating the top of the cone. The crater is formed so that approximately 25% of the full height of the cone is removed, with a pre-truncation height of 34 to 47 feet. The base diameter of the cone ranges from 68 to 94 feet, and a volume range of 1500 to 4000 cubic years.
After the piles are formed in such sizes and shapes, they are then over-saturated with water, which then percolates through the mixed ingredients and is expressed from the bottom of the pile by gravity, and pooled. The expressed liquid at the base of the cone, which is now rich in tannin liquors, is used to resaturate the pile and so provides the natural coloring agent for the material. Then, water flow is halted for inherent heat to generate by biological activity in the absence of water flow. The heat bakes-in the color and releases more tannins for extraction when liquid saturation is resumed. The process of resaturation and halting of the water flow to generate heat by biological activity is repeated until the desired color is achieved.